Milling tools for hobbing are often provided as integral tools wherein the milling inserts are placed along a helical line along a cylindrical tool body. In the manufacture of such tools, there may occasionally be problems of gaining access to machine seats for the milling inserts or the milling inserts themselves in those cases they are integrated in the tool body. This depends on the fact that it occasionally is narrow between axially consecutive revolutions of the helical line of milling inserts. This is a reason for milling tools for hobbing also being provided in the form of tools wherein the cylindrical tool body is composed of a plurality of disc-shaped segments, each segment usually embracing one turn of milling inserts in the helical line.
A plurality of different such embodiments of segment hobs are previously known. In DE 10 2005 029053 A1, a segment hob is disclosed that comprises a cylindrical tool body, which is composed of a plurality of separate segments. The separate segments are rotationally secured in relation to each other by means of loose, separate fitting bolts. In each end, there is an end piece, and the entire package of segments and end pieces is kept together by long, through screws. Centrally through all segments, a drive shaft extends, which in its one end is coupled to a machine tool, which is maneuverable to rotate the drive shaft. For the transfer of torque from the drive shaft to the tool, a wedge is countersunk in a groove on the drive shaft and is in engagement with internal grooves in the different segments.
A problem of this previously known segment hob is that the machining precision of the generated surfaces in the workpiece does not become sufficiently high for certain applications.